Unit 1 – Laboratory Mrs. Callender

How do I solve problems in chemistry?

A logical approach to solving problems or answering questions.

Develop a question or problem that can be solved through experimentation.

Make observations and research your topic of interest.

A proposed explanation of an observation. A proposed explanation of an observation. An educated guess. An educated guess. Must be testable. Must be testable.

Example: If soil temperatures rise, then plant growth will increase. ???

Develop and follow a procedure. Include a detailed materials list. The outcome must be measurable (quantifiable). Modify the procedure if needed. Confirm the results by retesting. Include tables, graphs, and photographs.

Must include a Measurement cm 23.5 cm 23.5 g 23.5 g 23.5 o C 23.5 o C 1.0 g/mL 1.0 g/mL Quantitative Descriptor. Texture Texture Color Color State of Matter State of Matter Smell Smell Sound etc. Sound etc.

On a piece of paper write which of the following observations are qualitative or quantitative cm6. red car o C7. 1,000 Km 3.Felt rough8. produced a gas 4.49 ants9. became solid 5.Is a square g

On a piece of paper write which of the following observations are qualitative or quantitative cm Quant.6. red car Qual o CQuant 7. 1,000 Km Quant 3.Felt rough Qual. 8. produced a gas Qual ants Quant9. became solid Qual. 5.Is a square Qual g Quant

The researcher is the observer, recording in a journal what he or she is seeing. Direct The researcher must depend on the reported information from other researchers.

A well tested explanation for a broad set of observations. A well tested explanation for a broad set of observations. May use models. May use models. May allow predictions. May allow predictions. Theories may change to explain new observations. Theories may change to explain new observations.

Presentation of results. A statement that summarizes results of observations, but does not explain them. A statement that summarizes results of observations, but does not explain them. Changes or is abandoned when contradicted by new experiments. Changes or is abandoned when contradicted by new experiments.

John watches his grandmother bake bread. He asks his grandmother what makes the bread rise. She explains that yeast releases a gas as it feeds on sugar.

John wonders if the amount of sugar used in the recipe will affect the size of the bread loaf?

“How does sugar affect the rising of bread?”

Develop an Experiment, Theory and maybe a Law.

Scientific MethodMaking Spaghetti Sauce ObservationSpaghetti sauce should be red. Hypothesis (prediction) Try a tomato sauce. TestHeat pot of tomato sauce. Observe resultTaste the sauce - bland. Revise hypothesis?Use tomato sauce and garlic! New test?Add garlic, taste - not so bland. Scientific TheoryThe Final Recipe.

Scientific MethodHigh Cholesterol ObservationPatient has high cholesterol Hypothesis (prediction) Certain chemicals may dissolve cholesterol deposits. TestGive 100 patients these chemicals, give 100 patients placebo. Observe resultSame number lower their cholesterol as placebo patients. Revise hypothesis? Try different combo of chemicals. New test?Re-run medical test. Observe results. Scientific TheoryLipitor reduces cholesterol.

Car won’t work?  Aliens drained the battery. Spaghetti is bland?  You were meant to eat bland food. Car won’t work?  Gods must be angry. Spaghetti is bland?  At the instant of tasting, tongue is transported to alternate dimension where all flavors are rendered nullified. Happens instantaneously.

No number of experiments can prove me right; a single experiment can prove me wrong.” Albert Einstein